Existing wireless base stations utilize deep drawn resonators (DDR) as a part of an amplification system. In general, there are two types of DDRs; integral and non-integral. In an integral, DDR a resonator and a filter body are formed as one component that makes up a cavity filter. Conversely, in a non-integral DDR the resonator and filter body are separate components making up a cavity filter.
FIG. 1 depicts a simplified view of a cavity filter 4 comprising a non-integral DDR 1. As shown, the non-integral DDR 1 rests on a filter body 2. Typically, the DDR 1 is fixed or otherwise connected to the filter body using a combination of a locked washer 3a and screw 3b. 
Referring now to FIG. 2 there is shown an expanded view of the area where the DDR 1 is connected to the body 2. In particular, FIG. 2 depicts a grounding contact area 2a where the DDR 1 is in contact with the body 2 to electrically ground the DDR 1 to the body 2. The typical connection of the DDR 1 to the filter body 2 depicted in FIGS. 1 and 2 presents certain challenges. One challenge is to insure that the DDR 1 remains electrically grounded to the filter body 2 as the temperature of the DDR 1 and body 2 changes (e.g., over a temperature range of −40 degrees Celsius to +90 Celsius). For example, when subject to temperature changes the torque relaxation of the screw 3b results in movement of the bottom portion 1b of the DDR 1 away from the body 2 (e.g. the screw 3b loosens up). As a result the DDR 1 may lose contact with the body 2 across, or at, the grounding contact area 2a. 
Yet further, the bottom portion 1b of the DDR 1 may deflect (e.g., bend) due to the force applied to the bottom portion 1b of the DDR 1 by a locked washer 3a as the washer 3a is forced against the bottom portion 1b by the screw 3b. The resulting force on the bottom portion 1b causes over compression of a portion of the bottom portion 1b of the DDR 1 around area 2b which, in turn, may cause the DDR 1 lose contact with the body 2 across, or at, contact point 2a. 
In either case, once the DDR 1 is no longer in contact with the body 2 across, or at, area 2a DDR 1 may become “ungrounded” which in turn may cause the frequency transmitted by the cavity filter to “drift” or vary which has adverse effects on the expected operation and performance of the amplification system. It is therefore desirable to provide methods and devices for grounding DDRs that minimizes or substantially eliminates a non-integral DDR from losing contact across, or at, a grounding contact area, which in turn minimizes or substantially eliminates frequency drift.